The Obama administration does not plan to finalize new regulations on the handling and disposal of toxic coalash before the end of 2011, U.S. Environmental Protection Agency officials said this week.

EPA Administrator LisaJackson revealed the news Thursday during an appearance before a House Appropriations Committee panel.

Jackson told lawmakers the EPA needs more time to review 450,000 public comments agency officials received on their regulatory proposal.

"It will take quite a bit of time to sort through," Jackson said, according to a report by the Bureau of National Affairs. She said the "final decision would be based on comment, science and law."

Coal-fired power plants generate more than 130 million tons of various cash wastes every year. The numbers have been increasing as more plants install scrubbers and other equipment to control air pollution, but shift the toxic leftovers from burning coal into ash and other wastes.

No single national program sets up a concrete regulatory plan for the handling of those "coal combustion wastes." Instead, the nation relies on a patchwork of state programs that vary in terms of their standards and their level of enforcement.

The issue simmered for years, with little focus from political leaders, until the spill of a billion gallons of coalash - containing an estimated 2.9 million pounds of toxic pollutants - from a Tennessee Valley Authority plant two years ago.

Despite initial tough talk on the issue, Jackson issued a regulatory proposal that did not settle on a particular strategy. Instead, EPA sought public comments on one approach that would regulate coalash as a hazardous waste, with nationwide regulations, oversight and enforcement, and an alternative that would leave actual regulation mostly up to the states.

Environmental groups prefer the tougher approach, and Earthjustice coalash expert Lisa Evans said Friday she doesn't see any reason for the EPA to delay finalizing the rule.